# newbie questions

• posted

Hi All,

I am a newbie to SW 2004, for some reason when I am sketching the cursor only changes to an orange dot when hovering over the origin. In the documentation it says that it should change to a different cursor when hovering over the origin. I've been getting around this by setting a coincident relation to the origin. Is there an option to turn snapping to the origin on or off?

Also, can anyone recommend a good read on sketch relations and dimensions? Thus far in my self taught learning process I've had the most trouble with defining geometric relations.

Regards, Bob

• posted

I'm not sure why you get an orange dot - it should change to the * indicating a point. You can also turn on the "point" selection filter and it should pick the origin. Try that and see if it makes a differnce.

As far as sketch relations go, start in the Help section under "sketches, relations." There it lists the possible relations & the entities that can utilize it. I even found a couple I didn't know about.

WT

• posted

Robert

About your involute gears, you can create cycloids, epicycloids, hypocycloids and trochoids utilizing the same construction techniques with a circle and dividing a circle tangent to the curve. These are similar to manual drafting techniques with circles, squares and triangles.

You also have the ability with Insert, Curve, Helix Spiral to create a curve that follows archimedes spiral.

The key is to utilize construction geometry and sketch relations to develop the more complex curves.

I would utilize a configuration in a large assembly, change the complex tooth profiles to a simplified tooth profile.

By definition two mating gears with have one point of tangency, this will not work for physical dynamics. So you definitely need a simple tooth if you want to see how the gears will move.

If you have these complex profiles in another CAD system, import them. If you have excel spread sheets, you can create the profile by reading in x, y, z coordinate data to create the sketch.

As far as documentation, SW includes the online tutorials, but you have to check during installation to install these tutorials. They are very helpful. I also have 4 pdf files at